是否有任何方法可以从查询结果pre-While循环中获取第一个结果？

Question

My site has a sizable table generated by a mysqli_query; the query includes a column 'messagetime':

$result = mysqli_query($cxn, 
"
  SELECT ......., messagetime
  FROM messages 
  ORDER by messagetime 
  DESC
"
);

I then generate the table (in php) with the help of a while loop:

echo "<table id='myTbl' class='newest' border='1'>";
echo "<th>Content</th> //etc.
echo "<tbody>";

while ($row = mysqli_fetch_assoc($result)) {

    // Fill the table body here

}

echo "</tbody></table>";

Nothing earth-shaking. However, the site uses polling to refresh the table, and I need to store the messagetime of the first result of the query in the table, like this:

echo "<table id='myTbl' class='newest".$newestTime."' border='1'>";

Right now, to capture the first (newest) messagetime, I am tweaking my While loop to do this:

$i = 0;
while ($row = mysqli_fetch_assoc($result)) {

     if ($i == 0) {
         echo "<table id='myTbl' class='newest".$row['messagetime']."' border='1'>";
         echo "<th>Content</th> //etc.
         echo "<tbody>";
     }

    // Fill the table here

     $i++;
}

echo "</tbody></table>";

However, this seems kind of hacky to me. Is there any way, without a subquery or union (since my query is actually the product of 2 joins, and is already expensive; this approach was described here), to simply pluck the first result from the query somehow, something like this?

$result = mysqli_query($cxn, 
"
  SELECT ......., messagetime, **first_messagetime_result AS newest_time**
  FROM messages 
  ORDER by messagetime 
  DESC
"
);

Thanks for any insight!

Answer 1

if ($result->num_rows > 0) {
    $row = mysqli_fetch_assoc($result)
    echo "<table id='myTbl' class='newest".$row['messagetime']."' border='1'>";
    echo "<thead><tr>";
    echo "<th>Content</th>"; //etc.
    echo "</tr></thead>";
    echo "<tbody>";
    do {
        // Fill the table here
    } while ($row = mysqli_fetch_assoc($result));
    echo "</tbody></table>";
}